Cleaning Up Alaska’s Abandoned Mines: Safety Closures and Restored Streams

Much of the mining on land now run by the National Park Service (NPS) took place before environmental compliance rules, so mined areas were not necessarily restored. The Park Service has had an Abandoned Mineral Land (AML) restoration program in Alaska since the 1990s. Lynn Griffiths writes that a substantial amount of disturbed land has been restored and numerous dangerous conditions made safe, but that more work remains.

A mine hazard at Wrangell-St. Elias (National Park Service photograph by Lynn Griffiths).

Making mines safe

The first aim is the safety of visitors. The hazards are very numerous: underground openings such as shafts and adits, deteriorating equipment, hazardous materials, explosives and deteriorating structures. The Kennecott mine in Wrangell-St. Elias National Park and Preserve, created to extract copper ore, is one example: it has 70 miles of dangerous underground workings with numerous openings, and mill buildings and equipment in decay. Unsafe mines are closed with steel gates made of manganal steel (also called jail cell steel), with polyurethane plugs, or by blasting to collapse the openings.

Restoring the land

The second aim is to restore disturbed land, mainly in flood plains and streamside habitat disturbed by placer mining. Projects have used innovative methods to remove hazardous waste, reduce hazards, reshape the mined area to approach its original contours, give streams their meanders back, stabilize banks, control sediment and replant with native plants.

Upper Caribou Creek, in the Kantishna area of Denali, shows what that means. Sections of the stream bed there had been mined from bank to bank. Crews removed hazardous materials and equipment from the park, leveled and contoured large tailings piles, set up more natural channel meanders and applied erosion controls.

Many mined areas remain to be restored and made safe for public use. The Park Service says it will continue the work to protect the public and to preserve mining history in Alaska's national parks.

Sources

• National Park Service, Alaska Park Science series The Legacy of ANILCA, Abandoned Mineral Land Restoration Activities in Alaska, by Lynn Griffiths; rewritten in hubnx's own words.